Tropical depression "Obet" will likely bring moderate to heavy rains in parts of Northern Luzon beginning Friday.

In its 5 p.m. weather bulletin today, the Philippine Atmospheric, Geophysical, and Astronomical Services Administration said "Obet" is forecast to gradually intensify and may reach the tropical storm category by Friday morning or Saturday.

"Obet" will trigger moderate to heavy with at times intense rains over the Babuyan Islands, Ilocos Norte, Apayao, and the northern portion of mainland Cagayan, while light to moderate with at times possible heavy rains will prevail in Batanes, the northern portion of Ilocos Sur, Abra, Kalinga, and the rest of mainland Cagayan.

Batanes, the Babuyan Islands, Apayao, Ilocos Norte, and the northern portions of Abra and Ilocos Sur will experience light to moderate with at times heavy rains throughout Saturday.

The tropical depression, which was last tracked over 920 kilometers east of extreme Northern Luzon, is decelerating while heading west-southwestward in the Philippine Sea.

A Tropical Cyclone Wind Signal may be hoisted in some areas in Northern Luzon from Wednesday night or Thursday morning while the prevailing northeasterly surface wind flow will bring strong to gale-force winds over Batanes, the Babuyan Islands, and the northern portions of mainland Cagayan, Apayao, and Ilocos Norte in the next 24 hours.

PAGASA said the highest TCWS to be raised is wind signal 2.

Moderate to rough seas over the seaboards of Central Luzon (from 1.5 to 3.5 m) and the western and eastern seaboards of Southern Luzon (1.2 to 3.0 m) will prevail due to the combined effects of the surge of northeasterly surface wind flow and "Obet."

The tropical depression may further intensify once it reaches the West Philippine Sea.

Meanwhile, the shear line will bring moderate with at times heavy rains over Cagayan including the Babuyan Islands, Apayao, Ilocos Norte, and Batanes until Thursday.

PAGASA warned that flooding and rain-induced landslides are likely under these weather conditions.